I dug my heels in on upgrading until about 2 months ago. Once you get CS figured out and are comfortable with it, it's hard to think about changing to a whole new system. But after biting the bullet, I must admit that I'm enjoying it MUCH more than I thought I would. It's not perfect, but a lot of things are fixed that really frustrated me with CS. The Pastures screen is great..no more digging through the Settings tab to find out who is where. Pedigrees are still a pain. Smart groups are awesome. Reports are much better. Group updates are easier, particularly weaning and preg checks. Right now, I am loving the Calving screen. So much easier.
With CS, I would get waay behind on making updates because I would have to go into the office and fire up the laptop. I put it off, a lot, and would sometimes get weeks behind. Now, I usually get on my iPad in the kitchen or while we're watching TV and make all of my updates. That's probably the best thing about Online, for me.